PURPOSE: To investigate the differential expression of TGFBIp in normal human and Fuchs endothelial corneal dystrophy (FECD) endothelial cell-Descemet's membrane (HCEC-DM) complex, and to asses the structural role of TGFBIp and clusterin (CLU) in guttae formation.
METHODS: HCEC-DM complex was dissected from stroma in normal and FECD samples. Proteins were separated by 2-D gel electrophoresis and subjected to proteomic analysis. N-terminal processing of TGFBIp was detected by Western blot analysis with two separate antibodies against the N- and C-terminal regions of TGFBIp. Expression of TGFBI mRNA was compared by using real-time PCR. Subcellular localization of TGFBIp and CLU in corneal guttae was assessed by fluorescence confocal microscopy.
RESULTS: A major 68-kDa fragment and a minor 39-kDa fragment of TGFBIp were identified on 2-D gels. Western blot analysis revealed an age-dependent proteolytic processing of the TGFBIp N terminus resulting in the increased formation of 57-kDa (P = 0.04) and 39-kDa (P = 0.03) fragments in older donors. FECD HCEC-DM showed a significant increase in the 68-kDa (P = 0.04), 57-kDa (P = 0.01), and 39- kDa (P = 0.03) fragments of TGFBIp. Real-time PCR analysis revealed that TGFBI mRNA was significantly increased (P = 0.04) in FECD samples. TGFBIp formed aggregates at the lower portions of guttae, next to Descemet's membrane, whereas CLU localized mostly on top of the TGFBIp-stained areas at the level of the endothelial cell nuclear plane.
CONCLUSIONS: The overexpression of proaggregative protein CLU, and proadhesive protein TGFBIp, have been colocalized in the guttae. Such findings provide us with a better understanding of the major contributors involved in the aberrant cell-extracellular matrix interactions seen in the guttae of patients with FECD.
The corneal limbus harbors corneal epithelial stem cells and contributes to the unique microenvironment of the stem cell niche. Corneal conditions, such as infections, tumors, immunological disorders, trauma, and chemical burns, often lead to the deficiency of the corneal stem cells, and subsequent vision loss. One key feature of limbal stem cell deficiency is corneal neovascularization. There is a delicate balance between pro-angiogenic and anti-angiogenic factors that, in a normal cornea, maintain an avascular state. A pro-angiogenic shift in this balance can occur due to various mechanisms, such as inflammation, gene mutations, physical breach in the limbal barrier, and decreased production of anti-angiogenic molecules. Currently available treatment options for limbal stem cell deficiency include allogeneic and autologous limbal transplants, and more recently, transplantation of alternative sources of epithelium, such as cultivated corneal and oral mucosal stem cells. Further studies are needed to investigate the combination of limbal and stem cell transplantation and concurrent anti-angiogenic therapy.
OBJECTIVE: To study the safety and efficacy of topical bevacizumab in the treatment of corneal neovascularization (NV).
DESIGN: In a prospective, open-label, noncomparative study, 10 eyes from 10 patients with stable corneal NV were treated with topical bevacizumab, 1.0%, for 3 weeks and followed up for up to 24 weeks.
MAIN OUTCOME MEASURES: The primary safety variables were the occurrence of ocular and systemic adverse events throughout the course of the study. The primary efficacy variables were neovascular area, the area of the corneal vessels themselves; vessel caliber, the mean diameter of the corneal vessels; and invasion area, the fraction of the total corneal area covered by the vessels.
RESULTS: From baseline visit to the last follow-up visit, mean reductions were 47.1% (standard deviation [SD], 36.7%) for neovascular area, 54.1% (SD, 28.1%) for vessel caliber, and 12.2% (SD, 42.0%) for invasion area. The decreases in neovascular area and vessel caliber were statistically significant (P= .001 and P< .001, respectively). However, changes in invasion area did not achieve statistical significance (P= .19). Visual acuity and central corneal thickness showed no significant changes. Topical bevacizumab was well tolerated with no adverse events.
CONCLUSIONS: Short-term topical bevacizumab therapy reduces the severity of corneal NV without local or systemic adverse effects.
APPLICATION TO CLINICAL PRACTICE: Topical bevacizumab provides an alternative therapy in the treatment of stable corneal NV.
TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00559936.
PURPOSE: To describe changes in demographics and pathogens for fungal keratitis cases diagnosed at the Massachusetts Eye and Ear Infirmary.
METHODS: Patient demographics, clinical and laboratory findings, treatment and outcomes of 46 cases of culture-proven fungal keratitis diagnosed from January 2004 through November 2007 were compared with 23 cases of fungal keratitis previously collected over a similar period from January 1999 through November 2002.
RESULTS: During 2004-2007, the rate of fungal keratitis was 1.0 cases per month, an increase from the baseline rate of 0.5 cases per month during 1999-2002. The proportion of cases caused by filamentous fungi increased from 30% (1999-2002) to 65% (2004-2007) (P = 0.01). Soft contact lens wear accounted for 41% of fungal keratitis cases in 2004-2007, as compared with 17% in 1999-2002. The majority of patients (70%) received oral antifungal treatment in addition to topical amphotericin B and natamycin. Seventeen patients (40%) required therapeutic keratoplasty. Patients with a history of corneal transplant had the highest rate of therapeutic keratoplasties (67%) and had the poorest visual outcome (40% counting fingers or less). In the contact lens group, 94% of patients maintained vision of at least 20/40 and only 12% required surgery to control the infection.
CONCLUSIONS: There has been an increase in fungal keratitis in the Boston area and a change in the causative pathogens and risk factors for infection. Filamentous fungi now account for the majority of fungal keratitis cases, whereas yeasts were the predominant pathogen in the past. Soft contact lens wear is currently the most common risk factor for development of fungal keratitis.